(a) Field of the Invention
The present invention relates to a syringe assembly used for animals, and more particularly to a syringe assembly for animals which, upon insertion of a syringe needle manually or by an injection gun, realizes the automatic injection of medication and ejection of the syringe from the animals by means of a self-propelled actuation mechanism.
(b) Description of the Related Art
Manually-operated injection instruments are most commonly used to inject medication into animals. When using such an injection instrument, the animal to be injected must be restrained to facilitate the injection process. That is, the animal must be firmly restrained so that the injection can take place without harm to the animal or the person administering the injection. This is both stressful to the animal and a time-consuming and strenuous process, making the administration of injections to a large number of animals particularly difficult.
In addition to manual injection instruments, various automatic injection instruments are in use including a syringe-type automatic injection instrument and a pressurized automatic injection instrument. However, when using such automatic injection instruments, the experience and skill of the administrator are very important for ensuring the successful and safe injection of the animal. Namely, since these automatic injection instruments instantaneously discharge the medication upon contact with the animal, the use of such instruments requires a high degree of expertise, especially considering the animal often moves during the procedure.
The pressurized automatic injection instruments automatically implant pellets into animals using air or gas pressure. A sensor attached on a head portion of the instrument initiates the injection process when put in contact with the animal. Such pellets, which are cylindrical or ovoid compressed masses of protein as an active ingredient, such as animal growth hormones mixed with pharmaceutical excipients, have been proven to display much better medicinal effects, durability and stability for animals than medication injected in a liquid form. However, it is a particularly difficult task to inject the hard pellets since the injection needs to be conducted instantaneously at an exact location on the body of a moving animal.
Another type of injection instrument used is a blowgun-type injection device. A syringe assembly- including a needle, a medication holder and a gas charge- is placed in a blowgun and shot toward the animal by the user aiming the blowgun and blowing on an end of the same in a direction toward the animal. Accordingly, the syringe assembly is directed to a desired location on the animal and gas is discharged upon impact of the needle such that the medicine in the medication holder is injected in the animal. However, a problem with such a device is that the syringe assembly is left remaining in the body of the animal after the injection procedure. Also, it is possible to harm the animal if the syringe assembly is directed on a part of the body which would injure the animal.
Accordingly, there is a need to develop an injection instrument for animals, especially for the injection of hard pellets, which requires little contact with the animal to be injected, operates instantaneously on exact locations of the animal body, requires minimal experience and skill to safely and successfully administer injections, reduces the chance of unsuccessful injections caused by a reflex action of the animal (resulting in the loss of part or all of the medication), and prevents the contamination of the needle.
The present invention has been made in an effort to solve the problems of the prior art and fulfill the above needs.
It is an objective of the present invention to provide a syringe assembly having a disposable injector incorporating a self-propelled actuation mechanism which enables self-ejection from the body after injection of medication is completed. In particular, it is an objective of the present invention to provide a syringe assembly which obviates the need to restrain animals.
It is another objective of the present invention to provide a syringe assembly which reduces the amount of manpower required and the injection time.
It is yet another objective of the present invention to provide a syringe assembly which enables efficient administration of injections such that injecting a large number of animals is easy.
It is still yet another objective of the present invention to provide a syringe assembly which requires minimal experience and skill to safely and successfully administer injections.
It is still yet another objective of the present invention to provide a syringe assembly which is disposal, thereby preventing needle contamination.
To achieve the above objectives, the present invention provides a syringe assembly including a hollow barrel having at least one catch therein; a needle part having a needle and a protrusion being caught by the catch; an elongated rod which is positioned inside the needle part and fixed on the end portion of the barrel opposite from a distal end of the needle, the rod having a catch member formed on an end portion thereof opposite the end inserted into the needle; a pulling member for pulling the needle part and the elongated rod to the opposite direction from the distal end of the needle; and a pressing member mounted to an end of the hollow barrel close to the distal end of the needle for releasing the protrusion of the needle part from the catch when external pressure is applied thereupon. The syringe assembly of the present invention further includes a protection member to seal the barrel and contain the ejecting elongated rod, a cover member to cover the needle with a small rod formed inside a closed end thereof, the small rod extending at a predetermined distance toward the needle to keep the same in place and to contain injection materials therein.